Monday, August 14, 2017

My wife, Grazia, collecting berries in the woods of Tuscany in a hot day of August. Maybe her ancestors were doing exactly the same, more or less in the same place, hundreds or thousands of years ago. Here, I present some reflections and some calculations showing that the EROI of this simple way of collecting food may be over 100, better than almost anything we have nowadays. Of course, no empire in history was based on hunting and gathering, but was that a bad thing?

The question of EROI - the energy return on energy invested - is raging nowadays, with some people insisting that a civilization cannot exist without an EROI of at least variously estimated values, at least 10 and higher (image on the right by Charles Hall). And that is said to mean we absolutely need sophisticated technologies, such as nuclear, in order to survive.

Yet, this morning I had been collecting berries in the wood with my wife and wondering: 'what is the EROI of what we are doing?' A reasonably good EROI, I am sure, enough for what our ancestors needed when they survived on hunting and gathering. All you have to do is to walk in the woods, find the berries and pick them up (and watch your step, you don't want to fall into a thorn bush). If our hunter-gatherer ancestors used this method, and if we are here today - their descendants - it means it was an effective strategy for survival. Collecting what you can find is an ancient and tested strategy that goes under the name of "gleaning" and it has accompanied humankind for millennia. It is a good strategy just because it is so simple: no tools, no written laws, no overlords, no police, no fences. And it works.

As I was collecting berries, I started thinking things. How to program a drone to collect berries, for instance. Sure: a perfect way to bring down the EROI of the whole thing to nearly zero. And to destroy the bushes forever. Humans are like this, with their attempt of "improving" things they always pull the levers in the wrong direction. And that means making things more complicated, needing more and more energy to keep them running, and then complaining that we don't have enough.

Of course, with more than seven billion humans on this planet, it is hard to think that we can go back to gleaning to feed them all. But for how long we can trust the expensive, complex, delicate, and terribly inefficient enterprise we call "industrial agriculture"? I can't say. What I can say is that collecting berries is a big satisfaction, as you see below.

And now some approximate calculations: Today we collected 2 kg of berries. According to the available data, berries contain 125 kJ/100g. So, the total collection was about 2500 kJ, about 700 Wh.

Now, it was about one hour of low-intensity work for two people, so let's say it involved a total of 50x2x1h = 100 Wh of human work. Then, I found values of 20-25% for the human metabolic efficiency of converting food to mechanical energy, it means we consumed some 400-500 Wh of food energy in order to collect 700 Wh.

Very approximate, or course, but the final result is an EROI = 1.4-1.7. Not comparable to crude oil, but probably more than enough for our ancestors to enjoy berries as a seasonal treat.

But, of course, no one ever lived on berries alone, not even in paleolithic times. The energy content of several kinds of foods that you can find in a natural environment may be more than an order of magnitude larger than that of blackberries. Walnuts are reported to have more than 10,000 kJ/100 g. If you can collect one kg/hour, as we did for berries, it means an EROI of more than 100 (!!). Larger than the mythical EROI of crude oil of a hundred years ago. Wheat and cereals, in general, have also high energy content, wheat is reported to have 15,000 kJ/kg, showing how gleaning could be an extremely efficient food gathering strategy.

So, life was simple and easy, once, until we decided to make it complicated and difficult.

Thursday, August 10, 2017

As part of a series of posts on photovoltaic energy as a metabolic revolution of the earth's ecosystem, I am reproposing a post that I published last year on "Cassandra's Legacy" with the title "Five Billion Years of Energy Supply".

It seems to be popular nowadays to maintain that photovoltaic energy is just an "extension" of fossil energy and that it will fade away soon after we run out of fossils fuels. But photovoltaics is much more than just a spinoff of fossil energy, it is a major metabolic revolution in the ecosystem, potentially able to create a "stereosphere" analogous to the "biosphere" that could last as long as the remaining lifetime of the earth's ecosystem and possibly much more. Here are some reflections of mine, not meant to be the last word on the subject, but part of an ongoing study that I am performing. You can find more on a similar subject in a paper of mine on Biophysical Economics and Resource Quality, (BERQ)

"Life is nothing but an electron looking for a place to rest," is a sentence attributed to Albert Szent-Györgyi. It is true: the basis of organic life as we know it is the result of the energy flow generated by photosynthesis. Sunlight promotes an electron to a high energy state in the molecule of chlorophyll. Then, the excited electron comes to rest when a CO2 molecule reacts with hydrogen stripped away from an H2O molecule in order to form the organic molecules that are the basis of biological organisms. That includes replacing degraded chlorophyll molecules and the chloroplasts that contain them with new ones. The cycle is called "metabolism" and it has been going on for billions of years on the earth's surface. It will keep going as long as there is sunlight to power it and there are nutrients that can be extracted from the environment.

But, if life means using light to excite an electron to a higher energy state, there follows that chlorophyll is not the only entity that can do that. In the figure at the beginning of this post, you see the solid state equivalent of a chlorophyll molecule: a silicon-based photovoltaic cell. It promotes an electron to a higher energy state; then this electron finds rest after having dissipated its potential by means of chemical reactions or physical processes. That includes using the potentials generated to manufacturing new photovoltaic cells and the related structures to replace the degraded ones. In analogy with the biological metabolism, we could call this process "solid state metabolism". Then, the similarities between the carbon-based metabolic chain and the silicon-based one are many. So much that we could coin the term "stereosphere" (from the Greek term meaning "solid.") as the solid-state equivalent of the well known "biosphere". Both the biosphere and the stereosphere use solar light as the energy potential necessary to keep the metabolic cycle going and they build-up metabolic structures using nutrients taken from the earth's surface environment.

The main nutrient for the biosphere is CO2, taken from the atmosphere, while the stereosphere consumes SiO2, taking it from the geosphere. Both metabolic chains use a variety of other nutrients: the stereosphere can reduce the oxides of metals such as aluminum, iron, and titanium, and use them as structural or functional elements in their metallic form; whereas the biosphere can only use carbon polymers. The biosphere stores information mostly in specialized carbon-based molecules called deoxyribonucleic acids (DNA). The stereosphere stores it mostly in silicon-based components called "transistors". Mechanical enactors are called "muscles" in the biosphere and are based on protein filaments that contract as a consequence of changing chemical potentials. The equivalent mechanical elements in the stereosphere are called "motors" and are based on the effects of magnetic fields on metallic elements. For each element of one of these systems, it is possible to find a functional equivalent of the other, even though their composition and mechanisms of operation are normally completely different.

A major difference in the two systems is that the biosphere is based on microscopic self-reproducing cells. The stereosphere, instead, has no recognizable cells and the smallest self-reproducing unit is something that could be defined as the "self-reproducing solar plant factory." A factory that can build not only solar plants but also new solar plant factories. Obviously, such an entity includes a variety of subsystems for mining, refining, transporting, processing, assembling, etc. and it has to be very large. Today, all these elements are embedded in the system called the "industrial system." (also definable as the "technosphere"). This system is powered, at present, mainly by fossil fuels but, in the future, it would be transformed into something fully powered by the dissipation of solar energy potentials. This is possible as long as the flow of energy generated by the system is as large or larger than the energy necessary to power the metabolic cycle. This requirement appears to be amply fulfilled by current photovoltaic technologies (and other renewable ones).

A crucial question for all metabolic processes is whether the supply of nutrients (i.e. minerals) can be maintained for a long time. About the biosphere, evidently, that's the case: the geological cycles that reform the necessary nutrients are part of the concept of "Gaia", the homeostatic system that has kept the biosphere alive for nearly four billion years. About the stereosphere, most of the necessary nutrients are abundant in the earth's crust (silicon and aluminum being the main ones) and easily recoverable and recyclable if sufficient energy is available. Of course, the stereosphere will also need other metals, several of which are rare in the earth's crust, but the same requirement has not prevented the biosphere from persisting for billions of years. The geosphere can recycle chemical elements by natural processes, provided that they are not consumed at an excessively fast rate. This is an obviously complex issue and we cannot exclude that the cost of recovering some rare element will turn out to be a fundamental obstacle to the diffusion of the stereosphere. At the same time, however, there is no evidence that this will be the case.

So, can the stereosphere expand on the earth's surface and become a large and long-lasting metabolic cycle? In principle, yes, but we should take into account a major obstacle that could prevent this evolution to occur. It is the "Allee effect" well known for the biosphere and that, by similarity, should be valid for the stereosphere as well. The idea of the Allee effect is that there exists a minimum size for a biological population that allows it to be stable and recover from perturbations. Too few individuals may not have sufficient resources and reciprocal interactions to avoid extinction after a collapse. In the case of the stereosphere, the Allee effect means that there is a minimum size for the self-reproducing solar plant factory that will allow it to be self-sustaining and long-lasting. Have we reached the "tipping point" leading to this condition? At present, it is impossible to say, but we cannot exclude that it has been reached or that it will be reached before the depletion of fossil fuels will bring the collapse of the current industrial system.

The next question is whether a self-sustaining stereosphere can coexist with the organic biosphere. According to Gause's law, well known in biology, two different species cannot coexist in the same ecological niche; normally one of the two must go extinct or be marginalized. Solid state and photosynthetic systems are in competition with each other for solar light. There follows that the stereosphere could replace the biosphere if the efficiency of solid state transduction systems were to turn out higher than that of photosynthetic systems. But this is not obvious. PV cells today appear to be more efficient than photosynthetic plants in terms of the fraction of solar energy processed but we need to consider the whole life cycle of the systems and, at present, a reliable assessment is difficult. We should take into account, anyway, that solid state creatures don't need liquid water, don't need oxygen, are not limited to local nutrients, and can exist in a much wider range of temperatures than biological ones. It means that the stereosphere can expand to areas forbidden to the biosphere: dry deserts, mountaintops, polar deserts, and more. Silicon based creatures are also scarcely affected by ionizing radiation, so they can survive in space without problems. These considerations suggest that the stereosphere may occupy areas and volumes where it is not in direct competition with the biosphere.

The characteristics of the stereosphere also allow it the capability of surviving catastrophes that may deeply damage the biosphere and that will eventually cause its extinction. For instance, the stereosphere could survive an abrupt climate change (although not a "Venus Catastrophe" of the kind reported by James Hansen). Over the long run, in any case, the earth's biosphere is destined to be sterilized by the increasing intensity of the solar irradiation over times of the order of a billion years. (and smaller for multicellular organisms). The stereosphere would not be affected by this effect and could continue existing for the five billion of years in which the sun will remain in the main sequence. Possibly, it could persist for much longer, even after the complex transformations that would lead the sun to become a white dwarf. A white dwarf could, actually power PV systems perhaps for a trillion years!

A more detailed set of considerations of mine on a related subject can be found in this article on "Biophysical Economics and Resource Quality, BERQ).

Notes: 1. I am not discussing here whether the possible emergence of the stereosphere is a good or a bad thing from the viewpoint of humankind. It could give us billions of years of prosperity or lead us to rapid extinction. It seems unlikely, anyway, that humans will choose whether they want to have it or not on the basis of rational arguments while they still have the power to decide something on the matter. 2. The concept of a terrestrial metabolic system called the stereosphere is not equivalent, and probably not even similar, to the idea of the "technological singularity" which supposes a very fast increase of artificial intelligence. The "self-reproducing solar plant factory" needs not be more intelligent than a bacterium; it just needs to store a blueprint of itself and instructions about replication. Intelligence is not necessarily useful for survival, as humans may well discover to their chagrin in the near future.

3. About the possibility of a photovoltaic-powered Dyson sphere around a white dwarf, see this article by Ibrahim Semiz and Salim O˘gur.4. The idea of "silicon-based life" was popularized perhaps for the first time by Stanley Weinbaum who proposed his "Pyramid Monster" in his short story "A Martian Odissey" published in 1933. Weinbaum's clumsy monster could not exist in the real universe, but it was a remarkable insight, nevertheless.

Olivia Judson published a very interesting paper this March on "Nature Ecology & Evolution". It is a wonderful cavalcade along 4 billion years of the history of the Earth, seeing it in terms of five "metabolic revolutions." It is an approach that goes in parallel with a paper that I wrote last year on BERQ; even though I focussed on the future rather than on the past. But my paper was very much along the same lines, noting how some of some of the major discontinuities in the Earth's geological record are caused by metabolic changes. That is, the Earth's changes as the life inhabiting it "learns" how to exploit the potential gradients offered by the environment: geochemical energy at the very beginning and, later on, solar energy.

Seen in these terms, the Earth system is a gigantic autocatalytic reaction that was ignited some four billion years ago, when the planet became cool enough to have liquid water on its surface. Since then, it has been flaring in a slow-motion explosion that has been going faster and faster for billions of years, until it is literally engulfing the whole planet, sending offshoots to other planets of the solar system and even outside it.

Judson correctly identifies the ability to control fire as the latest feature of this ongoing explosion. Fire is a characteristic ability of human beings and can be argued that it is the defining feature of the latest time subdivision of the planet's history: the Anthropocene.

Judson stops with fire, calling it "a source of energy" and proposing that "The technology of fire may also, perhaps, mark an inflection point for the Solar System and beyond. Spacecraft from Earth may, intentionally or not, take Earthly life to other celestial objects." Here, I think the paper goes somewhat astray. Calling fire a "source" of energy is not wrong, but we need to distinguish whether we intend fire as the combustion of wood, that humans have been using for more than a million years, and the combustion of fossil hydrocarbons, used only during the past few centuries. There is a big difference: wood fires could never take humans to contemplate the idea of expanding beyond their planetary boundaries. But fossil energy could fuel this expansion at most for a few centuries and this big fire is already on its way to exhaustion. If the Anthropocene is to be based on fossil fuels, it is destined to fade away rather rapidly.

Does this mean that we have reached the peak of the great metabolic cycle of planet Earth? Not necessarily so. Judson seems to miss in her paper that the next metabolic revolution has already started: it is called photovoltaic conversion and it is a way to transform solar energy into an electric potential, coupled with the capability of controlling the motion of electrons in solid state conductors. It is a big step beyond fire and thermal machinery (*). It is, by all means, a new form of metabolism (**) and it is generating a new ecology of silicon-based life-forms, as I discussed in a previous post that I titled "Five Billion Years of Photovoltaic Energy".

So, we are living in interesting times, something that we could take as a curse. But it is not a choice that we are facing: we are entering a new era, not necessarily a good thing for humans, but most likely an unavoidable change; whether we like it or not may be of little importance. It is a new discontinuity in the billion years long history of planet Earth that will lead to an increased capability of capturing and dissipating the energy coming from the sun.

The great chemical reaction is still flaring up and its expansion is going to take us somewhere far away, even though, at present, we can't say where.

A new lifeform, just appeared in the Earth's ecosystem:

(*) The Jews have been arguing for about a century whether electricity has to be considered a form of fire and therefore prohibited during the Sabbath. It is surely an interesting theological discussion, but for what we are considering here there is no doubt that fire (a hot plasma ignited in air) is not the same as electricity (controlled movement of electrons in solids)

(**) The supporters of nuclear energy may argue that the next metabolic revolution should be seen as the production of energy from nuclear fission or fusion. The problem is that the resources of fissionable material in the whole solar system are too small that they could hardly fuel a truly new geological epoch. As for fusion, we haven't found a technology able to control it in such a way to make it an earth-based source of energy and it may very well be that such a technology doesn't exist. But, on the sun, fusion works very well, so why bother?

Friday, August 4, 2017

Image above, from the Washington Post, 17 July 2017. Donald Trump seems to have been basically unaffected by the Russiagate campaign, even with those who disapprove him. Is it a sign that propaganda doesn't work anymore as it used to in the past?

It has been said that the best trick of the devil is to convince you that he doesn't exist. The same holds for propaganda, which draws most of its power from being able to convince people that it doesn't exist. Yet, it exists and its impact on people's lives has been gigantic. The more we try to ignore it, the more it affects us, especially those of us who claim to be immune from it.

Yet, it would seem that propaganda can work only when it can eliminate or marginalize the opposing voices in environments. Maybe the concept of "free press" is a little optimistic today in the Western World. Still, with the availability of the Internet, everyone can verify the media statements and there is no lack of opposing voices in the galaxy of the social media and the various independent media sites. That had led someone to prophesize "The end of Spin".

Can it be that propaganda has been weakened by the Web? Difficult to say, but some examples indicate that something has changed. A good example is the attack on Russia. It was done literally by the book, applying all the recipes that are known to work and have worked beautifully well in the past. In particular, it was based on demonizing the bad guy of the moment, Vladimir ("Vlad") Putin, accused to be a bloodthirsty dictator and compared to, well, you guess whom! The real objective, however, soon became to use the already done demonizing work to bring down the hated Donald Trump, accused over and over of connivance with the evil Russians,

Did it work? In short, no. At least for what it was its main purpose, that of bringing down Donald Trump, it was an abject failure. Despite the daily hammering of all sort of accusations about Trump being Putin's straw man, the idea just didn't stick. Even with those who disapprove Trump as president, the idea that he is somehow connected to, or working for, Russia and Putin ranks very low among the criticism list.

But that doesn't mean that the anti-Russian propaganda didn't work. Here are some recent Gallup poll results:

The barrage of anti-Russian news on the mainstream media has clearly had some effect, bringing 70% of Americans to have an unfavorable opinion of Russia. So, propaganda still works, it seems.

Yes, but only within some limits. If we compare these data with those for Iraq, we find that in 2003, 93% of Americans (!!) declared to have an unfavorable opinion of Iraq. That was a true triumph of modern propaganda that could obtain this result on the basis of a complete fabrication: that of the "weapons of mass destruction" allegedly deployed in Iraq. Such an extreme view of Russia seems unlikely to be attainable today.

So, could it be true that propaganda doesn't work anymore so well and so smoothly as it did in the past? Or is it Trump the maverick who is disrupting everything? The only thing we can say is that propaganda may have weakened a little, but it is still the formidable weapon it has been from the time when it was developed in its modern form by people such as George Creel and Edward Bernays.

Yet, in the long run, even the most wondrous contraptions are subjected to the Seneca Collapse. And one of the reasons why empires collapse is because of the mountains of lies that the elites tell to their subjects. It has happened in the past, it may happen again. It probably will.

Wednesday, August 2, 2017

The Stoics are the people on the top of the hill. They are applying Epictetus' maxim that says "What, then, is to be done? To make the best of what is in our power, and take the rest as it naturally happens." (Discourses, 1.1.17). (Image courtesy: Nate Hagens.)

There comes a point in which you have to acknowledge reality: Business as usual, BAU, is dead. Not that it would be impossible to avoid, or at least soften, the imminent disruption of our way of life caused either by resource depletion or climate change (or both). But that implies making sacrifices, renouncing something today for a better world tomorrow. And people are just not going to do that. We are not wired to plan for the future. We are wired to exploit what we have at hand.

The recent global events have shown that humans, worldwide, are unable to see priorities. The richest country in the world, the US, has turned its back to what science says about our faltering ecosystem, pursuing the impossible dream to return to an imaginary world of happy coal miners as England was at the time of Charles Dickens. The US is not the only example of a society that desperately tries cling to the old ways, refusing to change. Practically every country in the world is pursuing a dream of economic growth which, at this point, is just as impossible as a return to coal.

Does that mean we have to fall into despair? Some people seem to have arrived at this conclusion: there is nothing that can be done, therefore nothing that should be done. After all, what was so bad with the Middle Ages? And, anyway, human extinction would surely solve a lot of problems. Other take the opposite view, desperately hoping for some technological miracle that will lead us to leave the earth, colonize other planets, and mine the inexistent ores on asteroids.

What is to be done, then? Over the years, I found myself closer and closer to that group of ancient philosophers who lived during the times of decline of the Roman Empire who called themselves "Stoics" and who themselves the same question: what's to be done? The answer was given by Epictetus in his "Discourses:" It is "To make the best of what is in our power, and take the rest as it naturally happens". (1.1.17). And, after all, Seneca, to whom I credit the idea of the "Seneca Cliff", was a stoic, too!

Greens often exaggerate in inviting people to save energy and be happier by staying in the dark and eating insects. However, it is also true that sometimes wastefulness goes a few notches higher and becomes truly a scandal. It is the case of the ordinary disposable lighter. Bic alone produces almost a billion lighters per year and has produced some 20 billions of them in the past 30 years. The whole world production is probably of a few billion per year. A good example of a successful product, but is it a good product?

The disposable lighter is surely practical but also, if you think about it, a very bad deal. It contains some 5 cc of butane, that you pay, typically, more than $1. That means around $200 per liter, or $800/gallon. You wouldn't be happy to pay that kind of money when you refill the tank of your car. And, being powered by a fossil fuel, butane, every time you light up one you add some CO2 to the atmosphere, some of which will stay there for tens of thousands of years.

Then, the disposable lighter doesn't contain just non-renewable fuel but plastics manufactured from fossil fuels and also polluting. Then, it contains metals such as cerium, lanthanum, neodymium, praeseodymium and more. These metals are classified as "rare earths;" they are not so rare as the name seems to imply, but they are not so common, either. And the lighter is thrown away after use and it will never be recycled. The rare earths it contains will be lost forever.

Is all that enough to qualify disposable lighters as "the worst product ever marketed"? Well, everything can be questioned, but if you line up the characteristics of a bad product as 1) uses rare and non-renewable resources, 2) is not recycled and not supposed to be recyclable, 3) is manufactured on a large scale, 4) it has non-polluting and less expensive alternatives, there are few examples other than lighters for which you can tick all the four boxes. I can hardly think of anything so wasteful to set something on fire, no matter whether you are a professional arsonist or simply an ordinary smoker.

After all, what was so wrong with using the old matches? Matches contain only recyclable materials: wood, paper, phosphorous, sulfur. I can't see anything that can be done with a lighter that cannot be done with a match, except that a lighter can burn steadily for a longer time. But if your purpose is to light up a cigarette or a kitchen burner, it makes no difference. And, by all means, there is no way that a lighter would cost less than a match, at least if manufactured on a comparable scale.

So, disposable lighters are all an example of how a combination of financial factors and government regulations can push a bad product to dominate the market. It is, after all, what has happened with fossil fuels, still gathering large government subsidies, despite the damage they are doing to all of us.

In the case of lighter vs. matches, the playing field has been made unfavorable to matches from the beginning, because they have been traditionally taxed by governments (also lighters, in some cases, but not always). Add to that the rapid expansion of the cigarette market during the past decades, with some six billion cigarettes sold worldwide every year, and growing, some large companies saw their chance. They engaged in the large scale manufacturing of lighters and they crushed the match manufacturers, mainly small companies that couldn't match (indeed!) the financial power of large corporations. The advertising power, too, played a big role, with the appeal of colored and fashionable items that could also be collected. And it was world domination for the disposable lighter.

Could we reverse this demonic trend? Maybe there are signs of an inversion of the tendency and, not long ago, I saw again courtesy matchboxes appearing in an Italian Hotel. Maybe it was because finally (in 2015) the Italian government decided to abolish the tax on matches, a good idea that, unfortunately, arrived at least 50 years too late (the French Government did that in 1999). Whatever the case, it is high time that someone realizes that some ideas, such as disposable lighters, are evil to the bone. And that the mythical "free market" cannot turn evil into good.

But maybe you think that the old matches are passé? In this case, we have technologies for getting rid of the obsolete propane lighters without having to get back to the somewhat primitive matches. For instance, we have spark lighters that use only electricity. They are a solid state alternative to propane lighters in the same way as photovoltaic energy is a solid state alternative to fossil energy. In the picture, you see one of these super hi-tech lighters in the hands of my daughter, Donata.

So, eventually, we learn what's the good way to do things. Too bad that it is almost always too late.

Wednesday, July 26, 2017

During the "golden age" of science fiction, a popular theme was that of silicon-based life. Above, you can see a depiction of a silicon creature described by Stanley Weinbaum in his "A Martian Odissey" of 1934. The creature was endowed with a metabolism in which it would "breathe" metallic silicon, oxidizing it to silicon dioxide, hence it would excrete silica bricks: truly a solid-state creature. It is hard to think of an environment where such a creature could evolve, surely not on Mars. But, here on the Earth, some kind of silicon-based metabolism seems to have evolved during the past decades. We call it "photovoltaics." Some reflections of mine on how this metabolism could evolve in the future are reported below, where I argue that this new metabolic system could usher a new geological era which we might call "Stereocene", the era of solid state devices.

Abridged version of a paper published in 2016 in "Biophysical Economics and Resource Quality"

Ugo Bardi
Dipartimento di Chimica - Università di Firenze

The history of the earth system is normally described in terms of a series of time subdivisions defined by discrete (or “punctuated”) stratigraphic changes in the geological record, mainly in terms of biotic composition (Aunger 2007a, b). The most recent of these subdivisions is the proposed “Anthropocene,” a term related to the strong perturbation of the ecosystem created by human activity. The starting date of the Anthropocene is not yet officially established, but it is normally identified with the start of the large-scale combustion of fossil carbon compounds stored in the earth’s crust (“fossil fuels”) on the part of the human industrial system. In this case, it could be located at some moment during the eighteenth century CE (Crutzen 2002; Lewis and Maslin 2015). So, we may ask the question of what the evolution of the Anthropocene could be as a function of the decreasing availability of fossil carbon compounds. Will the Anthropocene decline and the earth system return to conditions similar to the previous geologic subdivision, the Holocene?

The earth system is a nonequilibrium system whose behavior is determined by the flows of energy it receives. This kind of system tends to act as energy transducer and to dissipate the available energy potentials at the fastest possible rate (Sharma and Annila 2007. Nonequilibrium systems tend to attain the property called “homeostasis” if the potentials they dissipate remain approximately constant (Kleidon 2004). In the case of the earth system, by far, the largest flow of energy comes from the sun. It is approximately constant (Iqbal 1983), except for very long timescales, since it gradually increases by a factor of about 10 % per billion years (Schroeder and Connon Smith 2008). Therefore, the earth’s ecosystem would be expected to reach and maintain homeostatic conditions over timescales of the order of hundreds of millions of years. However, this does not happen because of geological perturbations that generate the punctuated transitions observed in the stratigraphic record.

The transition that generated the Anthropocene is related to a discontinuity in the energy dissipation rate of the ecosystem. This discontinuity appeared when the ecosystem (more exactly, the “homo sapiens” species) learned how to dissipate the energy potential of the carbon compounds stored in the earth’s crust, mainly in the form of crude oil, natural gas, and coal). These compounds had slowly accumulated as the result of the sedimentation of organic matter mainly over the Phanerozoic era, that is over a timescale of the order of hundreds of millions of years (Raupach and Canadell 2010). The rate of energy dissipation of this fossil potential, at present, can be estimated in terms of the “primary energy” use per unit time at the input of the human economic system. In 2013, this amount corresponded to ca. 18 TW (IEA 2015). Of this power, about 86 % (or ca. 15 TW) were produced by the combustion of fossil carbon compounds.

The thermal energy directly produced by combustion is just a trigger for other, more important effects that have created the Anthropocene. Among these, we may list as the dispersion of large amounts of heavy metals and radioactive isotopes in the ecosphere, the extended paving of large surface areas by inorganic compounds (Schneider et al. 2009), the destruction of a large fraction of the continental shelf surface by the practice known as “bottom trawling” (Zalasiewicz et al. 2011), and more. The most important indirect effect on the ecosystem of the combustion of fossil carbon is the emission of greenhouse gases as combustion products, mainly carbon dioxide, CO2, (Stocker et al. 2013). The thermal forcing generated by CO2 alone can be calculated as approximately 900 TW, or about 1 % of the solar radiative effect (Zhang and Caldeira 2015), hence a nonnegligible effect that generates an already detectable greenhouse warming of the atmosphere. This warming, together with other effects such as oceanic acidification, has the potential of deeply changing the ecosystem in the same way as, in ancient times, LIPs have generated mass extinctions (Wignall 2005; Bond and Wignall 2014).

Burning fossil fuels generate the exergy needed to create industrial structures which, in turn, are used to extract more fossil fuels and burn them. In this sense, the human industrial system can be seen as a metabolic system, akin to biological ones (Malhi 2014). The structures of this nonbiological metabolic system can be examined in light of concepts such as “net energy” (Odum 1973) defined as the exergy generated by the transduction of an energy stock into another form of energy stock. A similar concept is the “energy return for energy invested” (EROI or EROEI), first defined in 1986 (Hall et al. 1986) [see also (Hall et al. 2014)]. EROEI is defined as the ratio of the exergy obtained by means of a certain dissipation structure to the amount of exergy necessary to create and maintain the structure. If the EROEI associated with a dissipation process is larger than one, the excess can be used to replicate the process in new structures. On a large scale, this process can create the complex system that we call the “industrial society.” The growth of the human civilization as we know it today, and the whole Anthropocene, can be seen as the effect of the relatively large EROEI, of the order of 20–30 and perhaps more, associated with the combustion of fossil carbon compounds (Lambert et al. 2014).

A peculiarity of the dissipation of potentials associated with fossil hydrocarbons is that the system cannot attain homeostasis. The progressive depletion of the high-EROEI fossil resources leads to a progressive decline of the EROEI associated with fossil potentials. For instance, Hall et al. (2014) show that the EROEI of oil extraction in the USA peaked at around 30 in the 1960s, to decline to values lower than 20 at present. A further factor to be taken into account is called “pollution,” which accelerates the degradation of the accumulated capital stock and hence reduces the EROEI of the system as it requires more exergy for its maintenance (Meadows et al. 1972).

Only a small fraction of the crustal fossil carbon compounds can provide an EROEI > 1, the consequence is that he active phase of the Anthropocene is destined to last only a relatively short time for a geological time subdivision, a few centuries and no more. Assuming that humans will still exist during the post-Anthropocene tail, they would not have access to fossil fuels. As a consequence, their impact on the ecosystem would be mainly related to agricultural activities and, therefore, small in comparison with the present one, although likely not negligible, as it has been in the past (Ruddiman 2013; Mysak 2008).

However, we should also take into account that fossil carbon is not the only energy potential available to the human industrial system. Fissile nuclei (such as uranium and thorium) can also generate potentials that can be dissipated. However, this potential is limited in extent and cannot be reformed by Earth-based processes. Barring radical new developments, depletion of mineral uranium and thorium is expected to prevent this process from playing an important role in the future (Zittel et al. 2013). Nuclear fusion of light nuclei may also be considered but, so far, there is no evidence that the potential associated with the fusion of deuterium nuclei can generate an EROEI sufficient to maintain an industrial civilization, or even to maintain itself. Other potentials exist at the earth’s surface in the form of geothermal energy (Davies and Davies 2010) and tidal energy (Munk and Wunsch 1998); both are, however, limited in extent and unlikely to be able to provide the same flow of exergy generated today by fossil carbon compounds.

There remains the possibility of processing the flow of solar energy at the earth surface that, as mentioned earlier on, is large [89,000 TW (Tsao et al. 2006) or 87,000 TW (Szargut 2003)]. Note also that the atmospheric circulation generated by the sun’s irradiation produces some 1000 TW of kinetic energy (Tsao et al. 2006). These flows are orders of magnitude larger than the flow of primary energy associated with the Anthropocene (ca. 17 TW). Of course, as discussed earlier on, the capability of a transduction system to create complex structures depends on the EROEI of the process. This EROEI is difficult to evaluate with certainty, because of the continuous evolution of the technologies. We can say that all the recent studies on photovoltaic systems report EROEIs larger than one for the production of electric power by means of photovoltaic devices (Rydh and Sandén 2005; Richards and Watt 2007; Weißbach et al. 2013; Bekkelund 2013; Carbajales-Dale et al. 2015; Bhandari et al. 2015) even though some studies report smaller values than the average reported ones (Prieto and Hall 2011). In most cases, the EROEI of PV systems seems to be smaller than that of fossil burning systems, but, in some cases, it is reported to be larger (Raugei et al. 2012), with even larger values being reported for CSP (Montgomery 2009; Chu 2011). Overall, values of the EROEI of the order of 5–10 for direct transduction of solar energy can be considered as reasonable estimates (Green and Emery 2010). Even larger values of the EROEI are reported for wind energy plants (Kubiszewski et al. 2010). These values may increase as the result of technological developments, but also decline facing the progressive occupation of the best sites for the plants and to the increasing energy costs related to the depletion of the minerals needed to build the plants.

The current photovoltaic technology may use, but do not necessarily need, rare elements that could face near-term exhaustion problems (García-Olivares et al. 2012). Photovoltaic cells are manufactured using mainly silicon and aluminum, both common elements in the earth’s crust. So there do not appear to exist fundamental barriers to “close the cycle” and to use the exergy generated by human-made solar-powered devices (in particular PV systems) to recycle the systems for a very long time.

Various estimates exist on the ultimate limits of energy generation from photovoltaic systems. The “technical potential” in terms of solar energy production in the USA alone is estimated as more than 150 TW (Lopez et al. 2012). According to the data reported in (Liu et al. 2009), about 1/5 of the area of the Sahara desert (2 million square km) could generate around 50 TW at an overall PV panel area conversion efficiency of 10 %. Summing up similar fractions of the areas of major deserts, PV plants (or CSP ones) could generate around 500–1000 TW, possibly more than that, without significantly impacting on agricultural land. The contribution of wind energy has been estimated to be no more than 1 TW (de Castro et al. 2011) in some assumptions that have been criticized in (Garcia-Olivares 2016) Other calculations indicate that wind could generate as much as about 80 TW, (Jacobson and Archer 2012), or somewhat smaller values (Miller et al. 2011). Overall, these values are much larger than those associated with the combustion of fossil fuels, with the added advantage that renewables such as PV and wind produce higher quality energy in the form of electric power.

From these data, we can conclude that the transduction of the solar energy flow by means of inorganic devices could represent a future new metabolic “revolution” of the kind described by (Szathmáry and Smith 1995). (Lenton and Watson 2011) that could bootstrap the ecosphere to a new and higher level of transduction. It is too early to say if such a transition is possible, but, if it were to take place at its maximum potential, its effects could lead to transformations larger than those associated with the Anthropocene as it is currently understood. These effects are hard to predict at present, but they may involve changes in the planetary albedo, in the weather patterns, and in the general management of the land surface. Overall, the effect might be considered as a new geological transition.

As these effects would be mainly associated with solid-state devices (PV cells), perhaps we need a different term than “Anthropocene” to describe this new phase of the earth’s history. The term “Stereocene” (the age of solid-state devices) could be suitable to describe a new stage of the earth system in which humans could have access to truly gigantic amounts of useful energy, without necessarily perturbing the ecosystem in the highly destructive ways that have been the consequence of the use of fossil fuels during the past few centuries.

Monday, July 24, 2017

One century after her death, Mata Hari remains for us the prototypical figure of the female spy. An extreme case of “femme fatale”; she is seen as someone who not only seduced men for her lust of money and power, but also for the greater lust of having them killed by the thousands on the battlefield. But she never was what she was said to be. Rather, she was one of the first victims of what we call today "fake news," also known as "propaganda", a set of techniques of mass manipulation being developed at that time and which today have reached near perfection.

A hundred years ago, on July 24, 1917, Margaretha Gertruida Zelle, known as Mata Hari, was sentenced to death by a military court in Paris on the accusation of being a spy for the Germans. She was said to have passed to them information that caused the death of “maybe fifty thousand French soldiers.”. She was shot a few months later.

Today, looking back at the acts of the trial, we can easily see the absurdity and the inconsistency of the accusations. If there ever was an example of a court of Marsupials, that was it. There just was no way that Mata Hari could have done what she was accused to have done. She was, rather, a scapegoat killed in order to distract the public in a moment when the war was going badly for France. Put simply: she was framed. It was one of the first examples of the deadly effects of propaganda (also known today as "fake news) which, at that time, was just starting to become a common feature of our world.

The trial was the endpoint of a career of dancer and performer that Margaretha Zelle had started when she came back to Europe from Indonesia, at that time called the "Dutch Indies". She had spent just a few years there as the wife of a Dutch Officer but that was sufficient for her to pick up something of the local culture that allowed her to claim that she was Buddhist. She also learned enough of the local language to be able to choose "Mata Hari" as her stage name, meaning (it seems) "The Light of Dawn". As a dancer, Mata Hari drew a lot of criticism at her times and it is likely that her dances were little more than strip teases with an Oriental flavor. Yet, she became very popular in Europe after she gave her first performance in Paris, in 1905.

As years went by, Mata Hari gradually gave up with stripping naked in public and she was said to have become a high-rank courtesan, seducing the rich and the famous (that, too, may be clouded by propaganda). During the war, she may have tried her hand at being also a secret agent, but it seems more likely that she was simply framed. In a certain way, the French and the German secret services collaborated in sending her to face the firing squad. The German saw her as a "propaganda point" to show how evil the French were in killing an innocent woman, while the French saw the trial as a way to show how tough they were against traitors (and traitoresses).

The trial and the detention of Mata Hari were a showcase of cruelty and intimidation. The last pictures we have of her show us no more the dancer that she used to be, but a woman physically destroyed by months of life in jail. After the execution, Mata Hari received also the ultimate insult, that of being denied a decent burial, of having her dead body dissected on a hospital table and having the pieces thrown away. They say that her mummified head was kept for some years in the museum of anatomy in Paris, before it was, too, thrown away and lost. She was denied the status of human being and considered rather as a sort of giant insect to be disposed of. The transformation of human beings into insects and their subsequent extermination is something that Kafka had already prophetically described in his story “the metamorphosis”.

In later times the anthropologist Roy Rappaport defined as “diabolical lies” those lies that “tamper with the very fabric of reality”. Today, we call those lies with the more neutral term of "fake news", as if they were just a fad that comes and goes. But fake news can kill and one of their victims was Mata Hari. The deadly mix of nationalism and propaganda that killed her was to continue and to explode in later years with the 2nd world war, leading Europe into the largest exterminations of innocent people that history has (so far) recorded. Mata Hari was among the first to be engulfed by this wave of senseless killing. She was killed in cold blood by people who were, most likely, perfectly aware that she was innocent.

It may well be that Mata Hari’s Oriental stance was not just a veneer to ennoble a little her strip teases, but it may also be that she had seriously studied Buddhism and other oriental ways while in the Dutch Indies. Her behavior at her execution, her calm, her evident belief that death was simply a passage, may tell us that her Buddhism was not just a pose but something that she had taken by heart. A hundred years later, we may still learn something from her story.

These notes are based mainly on the book by Rusell Warren Howe, "Mata-Hari. The true story". Editions de l'Archipel, Paris 2007, and on the near contemporary report by Emile Massard "Espionnes À Paris" (Gallimard, 1922), but there is lot of material on her story. Whereas earlier on there was still some discussion on whether she could really have been a spy, today the prevalent opinion is that she wasn't.

Wednesday, July 19, 2017

A silly idea that seems to be coming straight from a science fiction story of the 1950s. Mining the asteroids wouldn't just be outrageously expensive; the problem is that there is nothing to mine there. Yet, some people seem to take the idea seriously

It seems that, when we are in trouble, we tend to revert to our childhood memories, seen as happy times that, somehow, could return. That may explain why President Trump is dreaming of an impossible return to coal. He may see the idea through his memories of childhood as a time of happy miners and prosperous families.

Some others, instead, may revert to memories influenced by the science fiction of the 1950s, when the idea of "mining the asteroids" was commonplace. Jerry Pournelle wrote a delightful essay on this genre in 1980 under the title "Those Pesky Belters and Their Torchships". You may also remember the 1981 movie "Outland" starring Sean Connery and taking place in a mine on the moon of Jupiter, Io.

Nice memories, yes, could we ever mine space bodies for real? Well, the science fiction of the 1950s described many innovations that never appeared in the real world and most likely never will. Some because they are too expensive (flying cars) and some because they are contrary to the laws of physics (anti-gravity). Mining the asteroids falls straight into the "impossible" category for two reasons: the first is that it is too expensive and the second that it goes against the laws of geology (if not of physics). It wouldn't be physically impossible to mine the asteroids but there is nothing to mine there.

Let me explain: we can extract minerals on Earth because of the "energy credit" that comes from geological or biological processes (and often both) which have concentrated specific elements in some special regions of the crust. We call these regions "deposits" and we use the term "ores" for those deposits which are concentrated and pure enough that they can generate an economic profit from mining. Only ores are a useful source of minerals. Mining from the undifferentiated crust is simply unthinkable because of the enormous energy it would require (see my book "Extracted").

And there lies the snag with asteroids. The physical processes that created ores on our planet can take place only on planets which are both geologically and biologically active. As far as we know, asteroids never were. So, there are no ores on asteroids; nor there are on the moon or other "dead" space bodies. It is not impossible that there could be ores on Mars, which may have been geo-biologically active in a remote past, or perhaps on the moons of Jupiter, maybe geologically active today. But, for what we know, the best place in the solar system where to find ores is our planet, the good, old Earth (and, incidentally, as science fiction goes, the 2011 movie "Cowboys and Aliens" got the geology of the story perfectly right: the aliens come to Earth for its mineral resources).

So, no ores, no mining. And no ores on asteroids means no mining on asteroids (*). Of course, many asteroids are mainly iron, but it makes no sense to go there to mine iron if you consider that there is plenty of iron on Earth and you think of the costs involved with the idea of mining space bodies. It is an idea that just makes no sense.

Yet, we are seeing a spate of news that we could take as if someone really wanted to mine the asteroids. Possibly the most idiotic one appeared on "Futurism.com" with the title mentioning an asteroid "worth 10,000 trillion dollars". It seems that the author simply multiplied the mass of the asteroid, supposed to be all iron, by the current cost of iron per kg, arriving at such a meaningless number.

Other people seem to be peddling space mining and they may ask you money to finance their ideas on the basis of cute drawings which, indeed, remind the fictional spaceships of the 1950s. Others, including the Luxembourg government, seem to be willing to do exactly that: spend money on the idea of mining space, really! (at least, despite their attempt of selecting the worst possible ideas they couldn't imagine, they don't seem to be planning to invade Iraq).

Some people who should know better seem to have lost track a little of what they are saying. So, the French astrophysicist Jean-Pierre Luminet is reported to have declared that "Asteroids are full of pure and precious metals, such as gold, platinum, cobalt, etc, in quantities ten to a hundred times larger than what we can find in terrestrial mines." (let's just say that we can't pretend that astrophysicists know something of geology). The idea seems to be diffusing and I reported in a previous post how an acquaintance of mine reacted to my statements that we had resource problems with "but we shall colonize other planets!"

So, what to say? Just that when desperation sets in, idiocy often follows.

(*) commenter Ned noted that some meteorites have a platinum concentration higher than that of terrestrial ores. So, there may be an exception to the rule. Whether these asteroids could be actually mined, it is another question.

Monday, July 17, 2017

Benito Mussolini: Italy's leader for more than 20 years, met an ignominious end in 1945. It is a story that can illustrate what I called the "The Camper's Dilemma", how deception may be an operational strategy for governments and for elites.

How you react to a threat depends on how serious you consider it. Small or moderate threats don't deserve a strong reaction, while extreme, "existential" threats generate emergency measures. In between, there is an intermediate threat zone where you can think that it is a good idea to save yourself by cheating. It is what I called the "camper's dilemma." Imagine two campers in a forest inhabited by hungry bears. One possible survival strategy for each one of them is to cheat, convincing the other that there are no bears around and then quietly disappear, leaving him to be eaten.

When you have a model that looks good to you, the risk is to consider it as a hammer and see everything else as nails. But I think the "camper's dilemma" can tell us something about what's going on in the world. We all know that we are being cheated by our governments but, perhaps, the extent of the ongoing cheating still escapes most of us. So, as an example, let's revisit what happened in Italy during the second world war; when the military elites abandoned the army and the country in order to save themselves.

We all know how Mussolini's government made a number of truly gigantic strategic mistakes, engaging the country simultaneously against three of the greatest military powers of the time: Britain, the United States, and the Soviet Union. How could anyone think that was a good idea is baffling for us, but, evidently, Mussolini underestimated the threat that the country faced. He seems to have been thinking that the superior fighting spirit of the Italian soldiers would take Italy to victory despite its inferiority in terms of resources.

Reality made short work of this illusion when the Red Army defeated and destroyed the Italian expeditionary corps in Russia, some 250,000 men, in a campaign that lasted a few months from late 1942 to early 1943. It was a terrible blow for Italy. It showed that, no matter what was the fighting spirit of Italian soldiers, the Italian army couldn't cope against the larger and better-equipped enemies it faced.

I already discussed the defeat of the Italian forces in Russia in a previous post, noting that Italians were told nothing by their government about the true extent of the disaster. But let's go a little deeper in the matter, here. First of all, the elites of the country had access to all the information they needed to understand that the war was being lost. But there was a not-so-subtle difference between what Mussolini and his followers were thinking and what other people at the top, including the King of Italy, were thinking. Mussolini still hoped for a miracle, maybe coming from the "revenge weapons" that the Germans were developing. The King and his generals, instead, were mainly trying to save themselves by finding an agreement with the allies before it was too late. Both factions, however, needed to keep the country at war, at least for a while.

So, the Italian press kept lying to Italians while secret negotiations were ongoing between the King and the allies. Things come to a head on Sep 8, 1943, when Mussolini was deposed and arrested while an armistice was signed that stipulated the surrender of Italy. Then, the king and his entourage fled from the capital to find protection with the Allies. The Italian army collapsed in a matter of days, left without orders and without support, to be "eaten by the bear", that is by the German troops in Italy. The last ditch defense that Mussolini tried, later on, had no hope to succeed.

These events perfectly illustrate how the elites can deceive the people in order to save their necks. And, in this case, they succeeded beautifully. Up to the last moment, the people of Italy were being told that the fighting spirit of the Italian troops was high, that the enemies were suffering heavy losses, that victory was unavoidable because the decadent Anglo-Saxon plutocracies couldn't keep fighting for long. Then, in a few days, there was no army anymore and Italy had surrendered. Cheating at its best. (*)

It seems to be a general observation that, when facing a serious threat, the elites of a country can reason that the best strategy for them is to cheat the people and save themselves. In the present situation, the threat of global warming seems to be driving some elites to do exactly that. They deny the threat while at the same time maneuvering to save themselves by moving to higher grounds and equipping their mansions with air conditioning. For all they care, the rest of the people can drown or roast.

But, as the threat of climate change becomes clearer, the elites may discover that nobody can survive in an uninhabitable planet. Then, they may finally decide to try to do something to save the ecosystem from which we all depend. Unfortunately, when that time arrives it may well be too late.

(*)There are other similar cases in history. During the war, in Germany there were attempts to kill Hitler, that failed. Even in the Soviet Union, in 1942 Stalin emanated "order 227" ("not one step back") in order to re-establish discipline in the Soviet Army. In older times, we may cite the case of the kingdom of Naples invaded by the Piedmontese in 1860, when several Neapolitan generals defected to the other side. There are many more cases that show that the strategy of deception doesn't always work, but it does exist.

Saturday, July 15, 2017

Image above from the paper by Hull et al. "rarity in mass extinctions and the future of ecosystems" Nature 528, 345–351 (17 December 2015). Notice how the decline in the fossil abundance, takes the shape of a "Seneca Cliff". The article examines the current situation of the Earths's ecosystem and concludes that we are not yet falling down the cliff, but we might be in the future.

Sometimes, my colleagues make me think of the old joke, "I wouldn't want to belong to a club that accepts people like me as members." That happened to me once more when I read an interview to Smithsonian paleontologist Doug Erwin that was published with the title "We are NOT in the sixth mass extinction", ("The Atlantic," June 13, 2017). Here, Erwin states that the idea that we are in the sixth extinction is just "junk science".

If you wanted further proof that scientists are a bunch of unreliable nerds who live in a world of their own, you need to go no further. How can it be that the "sixth extinction" had become accepted science and then, suddenly, another one of those silly scientists comes up and says that it is not true? How can you believe a single word coming from them?

So. let's try to understand what this whole story is about. First, where does the idea of the sixth extinction come from? Perhaps it was popularized for the first time in a 2011 paper by Barnosky et al on Nature that dealt mainly with the megafauna extinction during the Holocene. Of course, the idea is older than that. If you look on "Google Scholar," the term "sixth extinction" produces more than 174,000 hits. If this is junk science, surely plenty of scientists seem to like this kind of junk.

So, why does Dr. Erwin defines as junk science a subject of study that looks perfectly legitimate and widely explored? The article in "The Atlantic" is just baffling. It starts with an image of the asteroid that's supposed to have killed the dinosaurs; then the title says "we are NOT in a mass extinction," then there follows a long review of all the ongoing extinctions, and then we read that "Erwin says no."

So, what are you supposed to understand from all this? Twice we are told that, yes, extinctions are ongoing, and twice that they are not. To add to the confusion, later in the article we are treated with paragraphs such as "“If we’re really in a mass extinction—if we’re in the [End- Permian mass extinction 252 million years ago]—go get a case of scotch,” he said." What in the world do you think could that mean?

Oh, boy, that life is complicated. Let's quit the silly article in "The Atlantic" and go see the original article in Nature where Erwin and his coauthors explain what they have in mind. And there, unlike in the Atlantic, we have an understandable text. Here are some excerpts from the article.

To date, the majority of extinction studies have been biased towards terrestrial species and charismatic megafauna and we know relatively little about changes in the abundance and ranges of the shelly marine invertebrates that would provide a direct link to mass extinctions in the fossil record.

From custodians of deep time, we need quantitative assessments of the fossil record of the present and future earth in order to accurately size up current biotic changes with the same filter through which we see the past.

Although extinctions are rare, the ecological ghosts of oceans past already swim in emptied seas.

You see the point? So far, we have focussed on the extinction of "charismatic" species, from the past one of mammoths, giant sloths, and the like to the ongoing ones of Elephants, tigers, cheetahs, and others. However, a true mass extinction sees the disappearance, or at least the the near disappearance of common species such as marine invertebrates. But that doesn't appear to be happening, yet.

There follows that, if someone in a remote future were to examine the fossil record for our times, he/she/it wouldn't see, not yet at least, the same kind of disastrous "Seneca Collapse" of the most common species that we see for the "big five" mass extinctions. Once a true "End-Permian-like" extinction were to start, it would be so rapid and destructive that nobody would be alive, discussing it.

That's it, folks: the title "We are NOT in the sixth mass extinction" simply means "we are not YET in the sixth mass extinction", but there are plenty of ongoing extinctions that prefigurate a true mass extinction ("emptied seas") for a non-remote future. That's because we know that most of the past mass extinctions (and perhaps all of them) were caused by the same phenomenon that's ongoing nowadays: the release of large amounts of greenhouse gases in the atmosphere.

Said in other words, imagine you are falling from the 10th floor. You are not yet splattered on the sidewalk and, if you really want to be precise, you shouldn't say that you are in the same condition of other people who fell from the same window in the past. Who knows? You might fall on something soft, or maybe learn how to fly while en route. Precision is precision, right?

So, the position taken by Dr. Erwin is scientifically correct, although it doesn't change what we know about the ongoing extinctions (and, as a personal opinion, I normally avoid branding the work of my colleagues as "junk science," even though I may not agree with them). We didn't go through a mass extinction, yet, because it is just beginning. The problem is that the meaning of the article in The Atlantic, and in particular its title, will NOT be generally understood. On the contrary, it will give plenty of ammunition to the throngs of those who claim that "CO2 is plant food," "the Earth is getting greener," "global warming is good for people"; and the like. It is already happening. As usual, when scientists say something that some people judge unpalatable, they are cheaters and liars. When a scientist says the opposite, he is suddenly defined as reliable.

I don't think Erwin is to be faulted in particular for this disaster in scientific communication. It happens all the time and especially when you stumble on journalists who tend to sensationalize what you tell them. Unfortunately, as scientists, we haven't yet learned how to communicate science to the public.

Who

Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014). His most recent book is "The Seneca Effect" to be published by Springer in mid 2017

Listen! for no more the presage of my soul, Bride-like, shall peer from its secluding veil; But as the morning wind blows clear the east,More bright shall blow the wind of prophecy,And I will speak, but in dark speech no more.(Aeschylus, Agamemnon)

Ugo Bardi's blog

This blog is dedicated to exploring the future of humankind, affected by the decline of the availability of natural resources, the climate problem, and the human tendency of mismanaging both. The future doesn't look bright, but it is still possible to do something good if we don't discount the alerts of the modern Cassandras. (and don't forget that the ancient prophetess turned out to be always right).

Above: Cassandra by Evelyn De Morgan, 1898

Chimeras: another blog by UB

Dedicated to art, myths, literature, and history with a special attention to ancient monsters and deities.

The Seneca Effect

The Seneca Effect: is this what our future looks like?

Extracted

A report to the Club of Rome published by Chelsea Green. (click on image for a link)

Rules of the blog

I try to publish at least a post every week, typically on Mondays, but additional posts often appear on different days. Comments are moderated. You may reproduce my posts as you like, citing the source is appreciated!

About the author

Ugo Bardi teaches physical chemistry at the University of Florence, in Italy. He is interested in resource depletion, system dynamics modeling, climate science and renewable energy. Contact: ugo.bardi(whirlything)unifi.it